Apparatus for phase and synchronism control



Aug. 26, 1947. c. DEAKIN E.TAL 2,426,131

APPARATUS FOR PHASE AND SYNCHRONISM CONTROL Filed July 17 2.944

INVENTORS G'EIPAlD DE/M'l/V l/tW/FX I? #159616 ATTURNIY Patented Aug.26,1947

ArrAaA'rUs roa PHASE AND srncnno- NISM CONTROL Gerald Deakin, New York,N. Y., and Henry F.

Her-big, Madison, N. J., assignors to International Standard ElectricCorporation, New York, N. Y., a corporation of Delaware Application July17,1944, Serial No. 545,332

20 Claims.

This invention relates to phase and synchronism control.

A principal object of the invention is to provide an apparatus formaintaining a rotary shaft in synchronism with another rotary shaft.

Another object of the invention is to provide amethod and apparatus forstarting the rotation of a shaft in synchronism and in phase alignmentwith another continuously rotating shaft.

Still another object of the invention is to provide an apparatus forindicating when a rotating shaft is in synchronism with another rotatingshaft and has the same phase relation thereto.

Still another object of the invention is to provide an indicatingmechanism including a rotatable pointer arranged to rotate insynchronism with an element mounted on a shaft at a distant point, tomaintain the same phase angle therewith, and to indicate that thedesired phase angle is being maintained.

-This invention is illustrated in the accompanying drawing, in which thesingle figure is a schematic diagram showing the circuit and apparatusin one form of .the invention.

In general, the invention makes use of a synchronous motor or phonicwheel at the controlled end of the system that follows pulses fromcommutator segments at the remote, controlling end, the commutator beingdriven by a nonsynchronous motor which continuously drives the shaft atthe controlling end. In the example chosen to illustrate the invention,this shaft is geared to the non-synchronous motor in a manner to rotateat a much slower speed than the motor. The synchronous motor or phonicwheel runs at a much slower speed than the nonsynchronous motor. It isgeared to the controlled shaft in such a manner that the latter runs atthe same speed as the driven shaft at the remote end. Provision is madewith pass by contacts on wheels attached to the two shafts in such amanner that one may be started in phase with the other and will remainin phase and flash a lamp as long as the apparatus isfunctioningcorrectly.

Referring to the drawing, pointer I, representing any element arrangedto be continuously rotated, is operatively connected to shaft 2 and canbe rotated under the control of motor 3 by means of suitable energizingcurrent from lin 4 when switch 5 is closed. Shaft 2 runs at a muchslower speed than motor 3, the reduction in speed being effected by agear train comprising pinion gear 6 carried by the motor shaft andmeshing with a gear I carried by an auxiliary shaft 8 which also carriesa pinion gear 8 which meshes with a gear l8 mounted on the shaft2.

At the controlled end it is desired to control pointer ll attached toshaft l2 in synchronism and in phase with pointer I. Pointer Ii attachedto shaft I2 is under the control of synchronous motor or phonic wheel l3through suitable reduction gears H and i5 and a clutch, mechanism to belater described.

Motor [3 is maintained in synchronism with shaft 8 by means ofcommutator device It which is operated by that shaft. The odd segmentsl6i of the commutator are connected to the grid ll of thermionic tube l8and the even segments l6-2 are connected to the grid iii of thermionictube 28.

a to the negative side of battery 22.

Gear l4 meshes with gear l5 under control of clutch magnet 2| and isarranged so that the gears engage when clutch magnet 2i is deenergized.Current from battery 22 is fed to brush 23 of the commutator device l6by way of switch 24 and thence through either of resistances 25 or 26,depending on the position of brush 23, The grids l1 and i9 are normallybiased negative by a battery 22--i so that no current flows in the platecircuits. g However, when switch 24 is closed. brush 23 alternatelyengages segments l6l and l6-2 and the positive potential of battery 22is connected to the respective grids I1 and I 9. Thus, the voltage dropacross resistance 25 is applied as a positive potential to grid ll oftube l8 with the result that current flows through the plate circuit oftube i8: similarly the voltage drop across resistance 26 is ap lied as apositive potential to grid IQ of tube 20 with the result that currentthen flows through tube 20. The plate circuit of tube I 8 includesoppositely positioned field magnets 21 and 28 of motor l3 in paralleland battery 22, while the plate circuit of tube 28 includes fieldmagnets 29 and 30 in parallel and battery 22.

Brush 3| on gear i8 and fixed conducting segment 32, brush 33 on gear l5and fixed conducting segment 34 are for the purpose of starting pointerII in phase with pointer I while the latter is being rotated.

Grid 35 of tube 36 is normally maintained at cathode potential. However,the grid circuit includes resistor 31 which is connected in parallelwith a neon lamp 38. This parallel connection of resistor 31 and neonlamp 38 is connected in a circuit including battery 33. switch 40, brushll, gear i8, brush 3!, segment 32, brush 42, gear l5, brush 33, andsegment 34. Whenever the is de-energized and out of mesh when the clutchis energized. This is for the purpose of eliminating current drainduring the normal running time. The magnetic clutch is connected to theplate 43 of the tube 33 and includes a front contact 44 adapted to beclosed for the energization of the clutch mechanism and a battery 43,the negative side of which is connected to the cathode 43 of the tube33. The contact 44 is adapted to be closed manually in order to energizethe clutch mechanism and thus disassociate the gears I4 and I3 providingthe grid 33 of the tube 33 is at a potential near the cathode 43. Bydriving the grid 33 negative, the plate-cathode current of the tube 33is shut 013 thus de-energizing clutch 2I which causes gears I4 and I3 tomesh again so that motor I3 can drive shaft I2 and pointer II. Whenclutch 2I is de-energized front contact 44 automatically opens and willnot close again until it is closed manually.

Referring now to the operation of the circuit and assuming that switches3, 24' and 40 are open, the non-synchronous motor 3 may be started byclosing switch 3 which connects the motor with the source of energizingcurrent from the line indicated at 4. This rotates the shaft 2 andpointer I through the gear train 3, I, 3 and I3. After motor 3 hasreached the normal speed, which, in the example chosen for illustration,may be about 1200 R. P. M., synchronous motor or phonic wheel I3 isready to be started.

Contact 44 on clutch 2| is now closed manually, thus closing thecircuitthrough the clutch magnet, battery 45, vacuum tube 33, betweenthe cathode 43 and plate 43 thereof, the grid and cathode under thiscondition being at substantially the same potential. This holds clutch2| in an inoperative or released condition and the gearing between motorI3 and controlled shait I2 disconnected. Shaft I2 and its associateddisc I3 are then set manually so that brush 33 is resting on contact 34.

Motor I3 is now started by spinning it electrically or manually by anyof the well known methods (not shown) and is thus brought up toapproximately its normal speed or a little greater, at which time switch24 is closed. The closing of switch 24 has the effect of swinging thegrids I1 and I3 of tubes l3 and 20 alternately positive as the brush 23of the commutator device I3 rotates over the segments. The odd' segmentsI3--I are connected to grid I1 of tube I3 and the even segments I3--2are connected to grid I3 of tube 20.

.When brush 23 is contacting an odd segment I3-I, as shown in thedrawings, grid I'l becomes positive with respect to the cathode of tubeI3 and the tube becomes conducting, causing current to flow throughfield magnets 21 and 23 back to battery 22.- This causes the armature tomove so that pole pieces which form armature poles move opposite fieldcoils 21 and 23. When brush 23 moves to an even commutator segment I3-2,grid l3 of tube, 20 becomes positive with respect to the cathode andtube 23 become conducting, so that coils 23 and 33 of motor I3 are nowenergized and attract armature poles thus rotating the armature so thatthe poles appear opposite coils 23 and 33. This causes motor I3 to fallinto step with the pulses produced by commutator device I3 and to bedriven at a constant speed with respect thereto.

Switch 43 is now closed. Thereupon the next time brush 3| passes overcontact 32, a circuit is obtained through battery 33, switch 43, brush4|, gear III, brush 3|, contact 32, brush 42, gear l3, brush 33, contact34, and neon lamp 33 in parallel with grid resistance 31 back to battery33. The negative side of battery 33 is connected to grid 33 and thepositive side is now connected to the cathode 43. This breaks thecircuit between the cathode 43 and plate 43 because the potential dropacross the resistor 31 produces a high negative potential on grid 33 inrelation to the cathode 43. This causes clutch 2| to release and openits contact 4'4, allowing gear I4 to engage gear l3 and start theindicating device II in phase with pointer I. Pointer II will thenrotate in synchronism with pointer I driven by motor I3.

As long as pointer II is in phase with pointer I neon lamp 33 will flasheach time the pointers rotate as brushes 3| and 33 simultaneouslyengaged contacts 32 and 34. The flashing of the lamp is thus anindication that pointer II is in phase with pointer I. If for any reasonpointer II gets out of phase with pointer I, the brushes will no longerengage the contacts simultaneously and therefore the neon lamp will notlight. If the neon lamp ceases to flash, therefore, indicating anout-oi-phase relation, it is only necessary to open switch 43 and closecontact 44 which will operate clutch 2| to disconnect gears l4 and I3.Pointer I I may then be set at the position where brush 33 engagescontact 34 and switch 40 closed again. This will cause the tube 33 toshut oil, as already described, when pointer I is in angular alignmentwith pointer II and brush 3I is in engagement with contact 32. Thecircuit through the clutch mechanism is thus again broken with theresult that gears I4 and I3 mesh with each other at this instant tocause pointer II to start in angular alignment with pointer I.

Pointer I may be designed to operate at any suitable speed as determinedby the gear connection to motor I3. In the arrangement shown in thedrawings for illustrative purposes pointer I is arranged to rotate atabout 4 rotations per minute. The normal speed of motor I3 is determinedby the number of poles provided in the armature, the number of segmentson the commutator I3, and the speed of the shaft 3 carrying the brush23. If eight poles are provided on the armature of motor I3 and thereare 43 segments, motor I3 will rotate at R. P. M.,

if brush 23 is rotating at 30 R. P. M. It motor I3 has ten poles, itwill rotate at 144 R. P. M. The gearing between motor I3 and pointer IIand between shaft 3 and pointer I is so designed that the two pointerswill operate in synchronism for a particular arrangement of armaturepoles and commutator segments.

It would be possible to connect the alternate commutator segments to thefield coils of motor I3 directly without the use of tubes and have anoperative structure. However, the discharge from the field coils in timewould injure the commutator contacts, whereas the circuit as shown hasno effect on the tubes and the energizing of the grids from thecommutator has no appreciable eflect on the commutator. It is quite searer probable that tube a could be replaced by a high speed relay.However, the tube has the advantage of speed and the minimizing of wearon the synchronizing contacts 32 and .due to the arcingthat would occurwithout a relay if used directly in the series circuit.

Various modifications of the invention will be apparent to one skilledin the art and I do not when said first shaft is'in a predeterminedangular position, a second brush carried by said second shaft, a secondcontact adapted to be engaged by said second brush when said secondshaft is in a-predetermined angular position, a circuit including saidcontacts and brushes, and

- means associated with said circuit to release said therefore desire tolimit myself to the specific I and .a moving contact therefor attachedto said shaft, means to connect alternate segments of said commutator tothe grid of said first thermionic tube, means to connect the remainingsegments of said commutator to the grid of said second thermionic tube,and means to connect the moving arm of said commutator to a source ofpotential more positive than the cathodes of said thermionic tubes,whereby said tubes are alternately operated as said shaft is rotated.

2. Apparatus of the class described comprising a first shaft, meanscontinuously to rotate said first shaft, motor means, means associatedwith said shaft to rotate said motor means insynchronism with said firstshaft, a second shaft, a clutch mechanism between said second shaft andsaid-motor means, trigger means to hold said clutch mechanism inreleased position, a circuit, means to close said circuit only when saidfirst and said second shafts are in the same phase relation, and meansto release said trigger means when said circuit is closed to cause saidclutch mechanism to operate, thus operatively connecting said secondshaft and said motor means. 1

3. Apparatus in accordance with claim 2, in

which said circuit includes an indicating device.'

4. Apparatus in accordance with claim 2, in which the trigger means tohold the clutch mechanism in released position comprises a relay havinga locking circuit which may be manually trigger means and cause saidclutch mechanism to connect said second shaft to said rotating meanswhen said circuit is closed by said brushes simultaneously engaging saidcontacts.

7. Apparatus in accordance with claim 6, in which said circuit includesan indicating device. 8. Apparatus in accordance with claim 6, in whichsaid circuit includes a lamp which will light when the contacts aresimultaneously engaged by the brushes.

9. Apparatus in accordance with claim 6, in whichthe clutch mechanism isheld in released position by means of the plate-cathode current i of athermionic tube and means is provided to produce a potential on the gridof said tube more negative than the cathode when the circuit includingsaid contacts and brushes is closed.

10. Apparatus of the class described comprising a first'shaft, meanscontinuously to rotate said shaft, means to produce a series of pulseswhen said shaft is rotated, a rotatable member,

means to rotate said rotatable member in synchronism with said firstshaft under control of said pulses, a second shaft, a clutch mechanismconnected between said second shaft and said rotatable member, a relayfor. controlling said clutch mechanism having a first contact, athermionic tube, a circuit for energizing said relay including theplate-cathode circuit of said thermionic tube and said first contact ofsaid relay, and means to shut off said thermionic tube when said firstand second shafts are in the, same angular position, so as to releasesaid relay and cause said clutch mechanism to connect said second shaftwith said rotatable member.

. 11, Apparatus in accordance with claim 10, in which the means to shutoff the thermionic tube comprises a circuit including two brushes oneat- 1 tached to each shaft and two contacts adapted operated and is heldlocked under control of the relay.

5. Apparatus in accordance with claim 2, in which the clutch mechanismis in a circuit including the plate-cathode circuit of a thermionic tubeand in which the release of said clutch mechanism is effected by causingthe grid of the tube to swing sufilciently negative to shut ofi thetube.

6. Apparatus of the class described comprising a first shaft, meanscontinuously to rotate said first-shaft, means associated with saidfirst shaft for producing a series of pulses when said shaft is rotated,a second shaft, rotating means for said second shaft, means to causesaid pulses to drive said rotating means at a speed insynchronism withthe speed of said first shaft, 9. second shaft, clutch mechanism betweensaid second shaft and said rotating means, trigger means to hold saidclutch in released position,

a first brush carried by said first shaft, a first contact adapted to beengaged by said brush to be engaged by the brushes simultaneously whenthe shafts are in the same angular position.

12.. Apparatus in accordance with claim 10, including an indicatingmeans and means to operate it when said thermionic tube is shut oil.

13. Apparatus of the class described comprising, first and secondrotatable means, means to rotate said first and second rotatable meansin synchronous relationship including a releasable clutch through whichsaid second rotatable means is driven, means to disengage said clutchwhereby said second rotatable means may be. set to a predeterminedangular position, and means to engage said clutch when said firstrotatable means is in a corresponding angular position, whereby saidfirst and second rotatable means are rotated synchronously incorresponding angular positions.

14. In apparatus 'of the character described,

the combination of, means at a first station to I second station, motivemeans at said second station and controlled by said electrical impulsesvto drive said second rotatable means at a speed dependentupon thespeed'of rotation of said first rotatable means, a releasable clutchmechtwo switches one of which is positioned at said first station andthe other of which is positioned at said second station and each ofwhich is closed when its respective rotatable means is positioned in thesaid predetermined angular position.

16. Apparatus as described in claim 14 wherein said control meansincludes an electromagnet which is energized to release the clutchmechanism, and circuit means to supply power to said electromagnetincluding an electronic device having a controlled circuit through whichcurrent flows to said electromagnet and a control electrode which isnormally biased to permit the flow of current through said controlcircuit and which is biased to prevent the flow of current whenthe tworotatable means are in their respective predetermined angular positions.

17. Apparatus as described in claim 14 wherein said motive means isdriven by power supplied through electronic means which has controlelectrode means upon which said electrical impulsesare impressed toexert the control effect.

18. Apparatus as described in claim 14 where-. in said control meansincludes a circuit having a pair of switches positioned respectively tobe opened and closed simultaneously by said first and second rotatablemeans when said first and second rotatable means are positioned inpredetermined angular relationship, and an electronic device having acontrol grid and biasing impedance means with the biasing impedancemeans connected in series with a source of potential in said circuitwhereby the closing of said switches produces a predetermined bias onsaid control electrode.

19. In apparatus of the character described, the combination of, acommutator device having a plurality of equally spaced segments and amov ing contactor which engages said segments'serially thereby tocomplete electrical circuits there- 8 through, means to rotate saidmoving contactor of the commutator device, an flelectric motorcomprising two sets of electromagnets each set of which is formed by aplurality of electromagnets with the electromagnets of the two setsbeing positioned alternately around an annular magnetic zone and anarmature having a plurality of spaced pole'pieces rotatably mounted tomove around said magnetic zone and to pass said electromagnets insuccession, a pair of electronic devices associated respectively withsaid sets of electromagnetsand each having a controlled circuit throughwhich current flows to said electromagnets and each having a controlelectrode, means constituting a source of power connected to saidelectronic devices, and circuit means connecting alternate segments ofsaid commutator device to one of the control electrodes and connectingthe other segmentsto the other control electrode, whereby the rotationof said moving contactor causes said control electrodes to be biasedalternately with the result that current flows to one set of saidelectromagnets and then the other and said sets of electromagnets allalternately energized so that said armature is rotated.

20. In the art of starting a first rotatable means rotating insynchronism with a second rotatable means, the steps of, producing aseries of electrical impulses in accordance with the speed of rotationof said second rotatable means, producing rotation under the control ofsaid impulses whereby the rotation is at the same relative speed as saidsecond rotatable means, imparting to said first rotatable means apredetermined angular relationship, and connecting first rotatable meansto be rotated by said rotation when said second rotatable means reachesan angular position corresponding to said predetermined angular positionof said first rotatable meansv GERALD DEAKIN. HENRY F. HERBIG.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number

